Endless track tread

ABSTRACT

An endless track tread involving the use of two pieces of plate which are welded together in offset relationship at both ends and drilled, or the use of a unitary section of plate of similar offset outline, for use as one of the plurality of overlapping and nesting treads of a self-propelled tractor vehicle.

United States Patent [72] lnventor Earl R. Woodward, Jr. [56] ReferencesCited Mars, Pa. UNITED STATES PATENTS Q12; $33 21 1969 1,238,079 8/1917Bager 305/11 [45] Patented y 1,316,627 9/1919 McKenzie.... 305/58X [73]Assignee Woodward Inc 1,952,545 3/l934 Gotshall 305/54X Mars Pa2,177,936 10/1939 Esters 1 305/51 3,336,088 8/1967 Bawer 305/54 [54]ENDLESS TRACK TREAD 2 Claims, 3 Drawing Figs. 52 us. c1 305/54 [51] Int.Cl B62d 55/26 [50] Field of Search 305/54, '51,

13,11, 40, 47, 48, 49, (Cursol'y) Primary Examiner-Richard J JohnsonAtt0rneyWi11iam J. Ruano ABSTRACT: An endless track tread involving theuse of two pieces of plate which are welded together in offsetrelationship at both ends and drilled, or the use of a unitary sectionof plate of similar offset outline, for use as one of the plurality ofoverlapping and nesting treads of a self-propelled tractor vehicle.

PATENTEnmwam 3578.824

INVENTOR.

EARL Rwooowmo, JR.

his ATTORNEY tively expensive alloy of high strength throughout towithstand friction and abrasion to which the endless track treads arenormally subjected. Furthermore the treads were usually arranged inbutting relationship.

I have overcome the above-named disadvantages by either machining anddrilling a thick section of plate into proper size and shape, or byproviding separate plates and welding them together in offsetrelationship to form a particular shape of tread for nesting with anadjacent tread to overcome the above-named disadvantages. j

A more specific object is to provide separate plates of either the sameor different alloys and welding their faces together ;while the platesare slightly offset as the top at one end and at the bottom at the otherend, so as to provide a novel-type tread that will nest and provide longlife.

Other objects and advantages will become more apparent from a study ofthe following description, taken with the accompanying drawing wherein:

FIG. 1 is a fragmentary side view of an earthmoving vehicle showingendless track treads of a construction embodying the present invention;

FIG. 2 is a top perspective view of one of the endless track treads of aconstruction, contemplated by the present invention, involving weldingtogether opposite faces of two separate plates, and;

FIG. 3 is a modification of the tread shown in FIG. 2 involving aone-piece plate which is machined and drilled to shape.

Referring more particularly to FIG. I of the drawing, numeral Igenerally denotes a tractor-type vehicle driven by endless belt or chain(not shown) such as used in army tanks and earthmoving vehicles,comprising 'a plurality of treads denoted by numeral 2 which areattached to an endless chain, such as used on a conveyor, and linkedtogether so as to form a continuous loop or chain of tread elementsadapted to nest together while at the top or bottom of the chain drive,as shown in FIG. 1.

FIG. 2 shows one form of the endless track tread comprising two separateplates 3 and 4, of about 55inch thickness each, which may be made eitherof the same alloy or of different alloys such as a greater wearing alloyfor plate 4 which engages the ground surface, than for the base plate 3which does not contact the ground surface but which has holes a 6drilled therein through which bolts are extended for connection to theconveyor chain drive. The plates 3 and 4 are slightly offset in thedirection of drive, as shown, and then welded together relates to thetread construction and 'along the weld line denoted by numeral 7. Therear edge (not shown in FIG. 2) may also be welded to form a rectangularoutline. Grooves 5 are then machined in the topplate 3, and holes 6 aredrilled in the bottom plate 4. Thus the bolt heads will rest on plate 4and will be confined within grooves 5.

FIG. 3 shows a modification of the tread shown in FIG. 2 wherein thetread, designated by numeral 10, is made of one unitary plate of aboutl-inch thickness which is machined at 12 and 13 to form offsets similarto those in FIG. 2 and wherein grooves 14 are drilled in the upper plate11 and holes 15 are drilled in the bottom plate 4. Since the unit ismade of a single plate, rather than being cast, it will be lessexpensive to manufacture and more resistant to wear and abuse inoperation. The offsets 12 and I3 enable adjoining treads to overlap ornest together as shown in FIG. 1. r j r As shown in FIGS. 2 and 3, thelateral end portions of each tread are inclined slightly in a directiontoward the interior of the chain and at right angles to the direction ofdrive to provide better clearance.

Thus it will be seen that I have provided a novel method of making orfabricating an endless track tread for earthmoving vehicles and thelike, which eliminates the necessity of casting the treads and, instead,permits the use of one, or a pair of plates welded together of the sameor different alloys and with opposite ends offset, to permit nestingtogether, whereby the cost of manufacture is reduced and yet thestrengthof the finished tread is considerably increased over that of acast tread.

While I have illustrated and described several embodiments of myinvention, it will be understood that these are by way of illustrationonly and that various changes and modifications may be made within thecontemplation of my invention and within the scope of the followingclaims.

Iclaim:

I. In an endless track comprising a plurality of treads in an endlesspath, each tread comprising a flat top metal plate stacked upon andcontacting a flat bottom metal plate, said top plate having a portionoffset from and overhanging an edge of said bottom plate, said bottomplate having an opposite edge which is offset from an edge of said topplate in the direction of drive, said top and bottom plates being weldedtogether along at least one of said edges, groove means extending onlythrough said top plate, and a plurality of holes extending only throughsaid bottom plate in registry with said groove means through which boltsmay be projected for fastening to said endless track, said top platecontacting said bottom plate throughout its entire bottom surface areaexcept for said offset portions and said groove means.

' 2. Apparatus as recited in claim I wherein said top and bottom platesare welded together along both said edges and wherein each tread haslateral end portions which are inclined slightly towards the interior ofthe track in a direction at right angles to the direction of drive.-

1. In an endless track comprising a plurality of treads in an endlesspath, each tread comprising a flat top metal plate stacked upon andcontacting a flat bottom metal plate, said top plate having a portionoffset from and overhanging an edge of said bottom plate, said bottomplate having an opposite edge which is offset from an edge of said topplate in the direction of drive, said top and bottom plates being weldedtogether along at least one of said edges, groove means extending onlythrough said top plate, and a plurality of holes extending only throughsaid bottom plate in registry with said groove means through which boltsmay be projected for fastening to said endless track, said top platecontacting said bottom plate throughout its entire bottom surface areaexcept for said offset portions and said groove means.
 2. Apparatus asrecited in claim 1 wherein said top and bottom plates are weldedtogether along both said edges and wherein each tread has lateral endportions which are inclined slightly towards the interior of the trackin a direction at right angles to the direction of drive.